1. Field
Example embodiments relate to a method of manufacturing a semiconductor device, and more particularly, to a method of manufacturing a semiconductor device including an isolation process.
2. Description of the Related Art
In general, unit transistors, e.g., unit cells, of a semiconductor device may be electrically insulated using an isolation layer. The isolation layer may include a field oxidization layer formed by selectively oxidizing a semiconductor substrate, for example, a silicon substrate, using Local oxidation of silicon (LOCOS) or a trench isolation layer formed by filling an isolation layer in a trench prepared by etching a semiconductor substrate to a fixed depth.
The field oxidization layer may be undesirable in terms of integration, and thus, may not be used as semiconductor devices are highly integrated devices. Instead, the trench isolation layer may be used in most cases. Because the trench isolation layer is formed on the trench prepared by etching a semiconductor substrate to a fixed depth, a semiconductor device may be highly integrated in one plane.
However, in the trench isolation layer, a depth of the trench may be larger for insulation between unit cells and a width (breadth or diameter) of the trench may be smaller to allow for higher integration. In particular, if a depth of the trench is not large, the unit cells may not be electrically insulated. An insulation layer may be filled in the trench when the trench insulation layer is formed. However, when a depth of the trench is larger and a width of the trench is smaller, the insulation layer may not be properly filled in the trench. When the insulation layer is not properly filled in the trench, the unit cells may not be electrically insulated.